This invention relates to a protective shield for use on a basic oxygen steelmaking furnace. Such furnaces, known in the art as a BOF, comprise large open ended steelmaking vessels which have thick refractory linings for protecting their outer steel shells from the molten metal and high temperatures contained within the vessels during the refining process. Such BOF vessels are usually mounted within a water-cooled trunnion ring which permits rotation of the vessel about a horizontal axis for charging and tapping operations and also functions as a heat sink transferring heat away from the hot steelmaking vessel walls.
Even though the BOF vessel is protected from the high refining temperatures by both its thick refractory lining and the heat sink effect of the water-cooled trunnion ring, there have been instances when the molten steel, being refined within the vessel, has burned through both the refractory lining and outer steel shell of the vessel. When such unexpected failures happen, the molten steel can erupt from the burn through area within the vessel wall and penetrate the water-cooled trunnion ring causing a massive steam explosion and considerable damage to the furnace and surrounding facilities. These occasional, violent explosions, have led to attempts to develop protective shields located at strategic positions along the inside wall of the water-cooled trunnion ring. However, past protective shield designs have failed because when such structures are installed within the narrow confines between the BOF trunnion ring and the steelmaking vessel they interrupt normal transfer of heat from the hot steelmaking vessel to the cooling water within the trunnion ring, radiate heat back toward the BOF vessel, and cause hot spots within the vessel wall resulting in structural damage.